This invention relates to assemblies for pumping from a container, dispensing and heating or cooling edible viscous food products having the viscosity of ketchup, mustard, melted cheese, sour cream, salsa or the like. More specifically, the invention relates to a peristaltic pumping and dispensing assembly with housing and heating/cooling flow channels for dispensing food products with such viscosity.
In the prior art, viscous food products of the viscosity of ketchup, mustard, melted cheese and the like, have been heated and dispensed from containers by pumping assemblies. Assemblies such as that in U.S. Pat. No. 5,579,959, use a pumping chamber and dispensing chamber with first and second valves associated therewith wherein the pump action draws the viscous food product into the pumping chamber during an intake stroke and forces the viscous food product through a spout tube during compression pumping action.
In the prior art, dispensers using peristaltic pumps have been employed to dispense viscous food products, as for example, disclosed in U.S. Pat. Nos. 4,513,885 and 4,690,307. In both said patents peristaltic pumps are used to force viscous food product from a container through a discharge tube. A pivotally mounted cam plate is used to hold the discharge tube in position against the rollers of the peristaltic pump rotor. The cam plate can be placed in an open or unlocked position so that the discharge tube can be positioned adjacent the rollers of the rotor. The cam plate can then be moved to a closed position and locked such as by a lock pin to press the discharge tube firmly against the rollers of the rotor. In this locked position, an operating handle is pivoted to rotate the rotor and its rollers so that pressure of the rollers against the discharge tube forces viscous food product from the container through the discharge tube and out a discharge fitment. However, the cam plates in those patents are held rigidly in fixed position and do not allow play between the cam plate and the discharge tube. As a result, the force against the discharge tube can be too tight to either block or overly impair flow therethrough, or on the other hand be too loose so that the viscous food drips. Further, for devices in which the position of a cam plate is fixed relative to the rollers, when different size discharge tubes are used, there will be a variance in the amount of force applied by the rollers against the tube during pumping. This also can cause blocking or over impairment of flow, or excessive flow and dripping. There is thus a need for a device wherein an approximately constant force can be applied to a discharge tube used with a peristaltic pump for discharging viscous food products at a proper flow rate.
With heated viscous food products, it is important that the product, such as melted cheese, be maintained at certain sanitary temperatures so that bacteria growth will be impaired and the food will be safe to eat. With a peristaltic pumping arrangement, it is, therefore important and desirable, to have a heating system which not only heats the food in the container, but which also heats the discharge tube and the discharge outlet so that bacteria growth is impaired in those areas as well.